Stovepipe casing



Oct. 4, 1932.

M. R. sHlPLEY ET Al..

sToVEPIPE `c AsING Original Filed April 5, 1927 4 She'etS-Sheeb 1 SH/PLEF H. 772007- 1 WML/HM oL/vf C. 772007,

0.6i- 4, 1932. M. R. sHlPLEY ET AL 1,881,379

STOVEPIPE GASING l original Filed April 5. v1927 4 sheets-sheet 2 50 -1 Y f-AA/f-:A/TORS:

Oct. 4, 1932. M, R SHiPLEY ET AL sTovE'PIPE cAsING Original Filed April 5. 1927 4 Sheets-Sheet 5 [//EA/TORS UCL 4, 1932 M. R. sHlPLEY ET AL 1,881,379

STOVEPIPE CASING Original Filed April 5. 1927 4 Sheets-Sheet 4 all( HTT'ORA/Elf.

Patented Oct. 4, 1932 UNITED STATES PATT OFFICE MARION' R. SHIPLEY, OF HERMOSA BEACH, AND WILLIADI A. TROUT' AND OLIVER C.

TROUT, OF LOS ANGELES, CALIFORNIA; SAID ASS-IGNORS, BY 'LESNE ASSIGN- MENTS, TO- LOS ANGELES MANUFACTURING COMPANY, INC., OF LOS ANGELES, CALI*- FORNIA, A CORPORATION OF CALIFORNIA l s'rovnrrrn cAsING Original application filed April 5, 1927, Serial No. 181,101. Dvidedvand this application med-February 29, 1928. Serial No. 257,934. l l I. 4

This application is a division of our ap-l plication entitled Stovepipe casing and method of making same, Serial No. 181,101, filed April 5, 1927 which terminated in United States Patent No. 1,670,639 of May. 22, 1928. v n

This invention relates to the art of manufacturing oil well drilling. equipmentand it relates particularly to an improvement in stovepipe casing made from sheet metal. 'l

As an oil well is drilled, a well casing is at certain intervals' advanced into the ,hole for reinforcing the wall against cave-ins, excluding ground water, and to` yif'orm a smooth walled lining for the well through which drilling tools may be easily extended and operated to finish drilling the well.

Two types of casingare used for this purpose, screw casing and stovepipe casing. Screw casing is made up from sheet wrought iron which is rolled into cylindrical form and welded. Each end of the casing is provided with screw threads which are adapted to be screwed into couplings for joining ad` jacent sections together.

Stovepipe casing, as made at present, comprises inner and outer layers of comparatively soft sheet metal which are rolled intol cylindrical form and secured together leither by riveting or by rolling inter-engaging corrugations in the two layers after they areA placed together. The sections of the outer and inner layers are staggered relative to each other and the entire linear tensile strength of the casing resides in the connection of each adjacent pair oi'sections, in each layer, by a section of the other layer which overlaps and is joined to said pair of sections by riveting, rolling, or some other method. Thus, each section of the inner layer overlaps and constitutes the onlyyconnection between an adjacent pair of sections of the outer layers. l

Due to the above, noted; method by which the stovepipe casing in general use is formed, it is necessary that both inner and outer lay-A ers be made of sott metal which wears away quickly when the drill pipe rubs against the inner layer. Any slight deviation of the hole from straight will cause such a rubbing, and Iit is common to have the inner layer oit casing worn in two,.thus causing the entire casing to part at. this point.

' In addition to this defect, the linear tensile strength oie stovepipe casing as built'at present is inadequate to stand the strain of supporting five hundred to several thousand feet of casing which is necessary in the installation of casing in a well. Far from being uncommon, it is almost the usual thing that when installing a long length of stovepipe casing, it will pull in two when partially lowered into place. A fairly high linear tensile strength is obtained inthe corrugated stovepipecasing, but the inwardly eX- tending corrugations wear through vmuch quicker, when the drill pipe starts to rub,l than the cylindrical wall of ordinary riveted stovepipe casing. And when the inner lami' nation thuswears in two, .the casing parts at'this point.

l .It is an object of our invention to provide a stovepipe casing which has a linear tensile strength equivalentto that of any of the present casings, but which will not part should the inner layer thereof be worn in two.V f

Moreover, each outward corrugation in lcorrugated casing forms a pocket which yfills up with cement as a cementing plug passes by in a cementing operation, the amount of cement thus wasted in a thousand feet ofY casing being excessive. ,Riveted casing, onthe other hand, is seldom truly cylindrical so that it is very ditlicult to form a fluidtight fit between a Acementing plug and the casing 'throughout the length of the casing. It is therefore an object lof our'invention to provide a stovepipe casing which has a smooth and truly cylindrical inner surface. which will make a uniformly fluid-tight fit withv a cementing plug as it passes down-- ward through the casing. f

It is alsoan object of ourinvention to pro-A vide a lstovepipe casing in which the inner layer may-be made of metal whichl is too hard to successfully punch or corrugate.

, The best ot stovepipe casing as now made leaks badly, even when new, and it is therefore a further obj ect'oi" our invention to progether.

Vide a stovepipe casing which is thoroughly water-tight under all normal operating conditions.

Other objects and advantages willbe made manifest in the following description and in the accompanying drawings, in which:

Fig. 1 is a diagrammatic view showing a well bore in which is inserted a preferred form of the stovepipe casing of our invention.

Fig. 2 is an enlarged vertical medial sectional view of a portion of the casing shown in Fig. 1.

'Figs 3, 4, 5, and 6 are views illustrating how the inner and outer lamination sections, which are utilized in the manufacture of our improved casing, are formed.

Figs. 7 to 10 inclusive illustrate how the inner and outer lamination sections are assembledin the formation of stovepipe casing.

Figs. 11 and 12 are detailed sectional views illustrating respectively a reinforcing fold and an outer section interlocking joint of our novel stovepipe casing.

Referring specifically to the drawings, Fig. 1 shows a portion of a well 15 which has been bored through a series of inclined strata 16, a geological formation which is frequently found above oil pockets. The well 15 is lined with a stovepipe casing 17 which has been cemented into place at its lower end so that the walls of the well hole have settled into Contact with the outer surface of the casing. The casing 17 is made up of sec-- tions or lengths 18, one of which is shown completely in Fig. 1, these lengths being about forty feet long and provided at their ends with couplings 19 whereby meeting ends of adjacent lengths are connected to- The couplings 19 may be of any desired character, the coupling atV present used' for this purpose being shown and described in United States Letters Patent No. 1,690,562 of November 6, 1928, issued to Oliver C. Trout for a stovepipe casing coupling. f

Each of the lengths 18 is made up of a tubular inner lamination 22 and an outer tubular lamination 23. The inner tubular lamination 22 is formed of a plurality of sections 24, of the same diameter, which are disposed end to end, with the ends thereof abutting. The tubular outer lamination 23 is formed of a plurality of sections 25 which are placed end to endlabout the tubular inner lamination 22 so that the adjacent ends of the sections 25 interlock. The outer tubular lamination 23 tightly grips the inner lamination 22 so that the outer sections are disposed in break-joint relation with the inner sections.

The details of thestructure of the novel stovepipe casing 17 is described as follows:

rI he sections 24 of the'inner lamination 22 are first formed, as shown in Fig. 3, by bend" ing a sheet 28 of high carbon steel by the use of forming clamps 29 about a mandrel 30. Opposite edges 31 and 32` of the sheet 28 are thus brought adjacent ,toeach other and are connected by the application of welding inai formed on the mandrel all have exactly the saine inner diameter. rlhe gauge of the high carbon steel sheet 28 is suliiciently accurate so that the outside diameter of the inner lamination sections 22 are also practically uniform.

, The sections 25`of the tubular outer lamination 23 are formed, as shown in Figs. 4, 5 and 6. A rectangular sheet o f duetile steel 35 is iirst formed in a break so thatl opposite edge portions 36 and 37 are bent from the body of the sheet 35, as shown in Fig. 4, and the central portion 38 of the sheet 35 is outstruck from the body thereof as shown. VThe sheet of metal 35 is now placed in a press, and the edges 36 and 37 and the outstruck proj ection 38 are pressed flat against the body of the sheet 35, as shown in Fig. 5. vThe bent portions 36 and 37 thus ferm ribs 39 andv40 on the opposite sides of opposite edges of the sheet 35 and the outstruck projection 38 forms a fold 41 exteifiding substantially parallel to the ribs 39 and` 40 and disposed substantially in the middle ofthe sheet 35 equidistant from the ribs 39 and 40.

The sheet 35 is now passed between a suitable set Vof roller dies which are disposed perpendicular'to the ribs 39 and 40 and the fold 41 and which roll the sheet of metal 35 inte a tubular outer lamination section 25, as shown in Fig. 6, having a slit 42 formed lengthwise in thewall thereof. The sheet 35 is rolled so that the rib 39 and the feld 41 are upon the outside of the section 25, and so that the rib 40 is disposed on the inside of the section 25. In rolling the sheetv 357 the end 43 fk thereof which carries the ribk 40 is stretched to form a bell 44`on the inside of the mouth of which the rib 40 is disposed. The bell 44 is of such length that an annular space 45 is provided above and adjacentto the rib 40 i' which is of the same axial depth as the rib 39. In addition to stretching the end portion 43 of the sheet 35, it is also necessary in rolling the section 25, to stretch the rib 39 and the fold 41 so that these will not tend to draw the upper and lower halves 46 and 47 of the section 25 out of true cylindrical shape.

The remaining operations to produce stovepipe casing are taken up with the assembly of the outer and inner lamination sections formed as above described. In this assembly aV first outer laminationsection 25, as indicated by `the numeral 48 in Fig. 7, is placed about two inner sections 22 which are indicated by the numerals 49 and 50 and` which -I inner sections49 and y is clamped,

in rig. 7.

, ing material leased. by

. tion 48 substantially halt of itsA length to a point indicated by the numeral 51. yEhe actual applying ci the outer section 48 to the inner sections 49 and 50, as just described, taires place prior to the step illustrated in f Fig. 7, and the section 48 in this prior operagauge clamps 52 is 'forced .into tight contact with theinner sections 49 and (2).` V'llhe adjacent edges of the slit 42 of the tion is tightly grippedby and 53' so, that the section 48 seccion 48 are then connected as by a welded seam 55 while the section 48 is thus clamped in position. ln the clamping operation, the clamp 52 is applied to the 'fold 41 of the sec tion 48, and the clamp 53 is applied to the body portions 46 and 47. vlfJhile but one, each,

of theclamps 52 and 58 is shown in the drawings, anyv suiiicient number oi these clamps may be employed te properly position the section 48 in tight gripping relation with the 50, while the welding of the seam 55 takes place.. When the seam 55 has been completed or a sufficient number of spot welds formed-through its length to hold the section 48 in the position in which. it the clamps are removed, and the outer section 48 with the inner sections 49 and gripped therein are rotated so that the seam is disposed downward as shown A second outer section 25, indicated bythe d numeral 58, is new slipped over the exposed half of the innere-action 50, and the bell 44 of the outer section 5 8 1s disposed about the rib 89 of the outer section 48 so that the Arib 5g 89 will lit into the annular space 45 of the bell of the section 58.V The clamp 52 is now placed about the .bell 4470i the section 58 and the bell 44 is forced inward into tight gripping relation with the rib 89 of the section 48, as clearly shown in the detailed sectional View of Fig. 12.

The clamp 58 is now placed about the lower half47 of the outer section 58 so as to 'tightly contract this into contact withthe inner section50. Spots oi weld- 60, as illustrated in Fig. 8, are new applied to vconnect the adjacent edges of the slit 42 ci' the section 58 where these edges are held closely together bythe clamps 52 and 58, and thereafter the clamps are re- A third inner section 22,V indicated the numeral 62 in Fig, 8, is now slid into the upper half 46 of the outer section 58 so as te abut against the upper' en'd of the inner section 50 at 51. rlhe clamp 52`is now placed about thefold 41 ot the outer section 58, the

' clamp 58 is'moyed upwardtoward said fold 41, andthe two clamps are'tightened into place to cause the portions oit the outer sec-.

tion 58 whichV they contact to tightly vgrip t the inner lsections 50 and 62. Further spots of welding material are applied while the clamps are in this position Vso as to unite other portions of the edges of the slit 42 of the section 58. By applying the clamps 52 and 58 to the upper half 46 of the section 58 and spot welding together the edges of the upper portion" of the slit 42, the outer lamination section 58 is brought into tight gripping relation with the inner lamination sections 50 and 62, and, due to the cylindrical gauging eiect brought about by the application of the gauging clamps 52 and 58, the outer section 58 and the inner sections 50 and 62 are united in a true cylindrical shape which they retain due to the welding together of the edgesl of the slit'42., When the section 58 has thus been entirely secured in place by the spot welding 60, the sections already assembled arel rotated so as to dispose the seam in the sec-tion 58 downward and the third outer section 25, as indicated by the numeral 65 in Fig. 8, is then applied to the outer section 58, the inner section 62 (and another inner section) in the same manner that the outer section 58 was applied to the outer section 48l and the inner sections 50 and 62.

As above indicated, the seams of adjacent outer sections 25 are disposed 180 apart. The seams of adjacent inner sections are like-V wise .diametrically opposed and the diametral plane of the inner section seamsis dis-v outer and inner sections are all disposedl either ninety or onehundred and eighty degrees apart, in the cylindrical composite wall of the stovepipe casing 17.

Vhen a suilicient number of inner and outer sections have thus been connected together to form a length 18, flange members oi the couplings 19 are applied to theend of the length in the manner described in the above noted application. The spot welds 60 are also joined by further application o welding material to form seams 66, as .clearly shown in Fig. 9.

The essential operations to form the casing of our invention are now completed. It is, however, advantageous to apply a packing 67 of welding material between the lower edge of each of the bells 44 and the adjacent outer surface of the next outer section 25. This .packing weld 67 is not required to strengthen the joint formed between adjacent outer sections, but is primarily for the purpose. of making the casing water-tight. Also, as a protection against the folds 41 catching von sharp rocks or otherobjects and being flared outward, a series of spot welds 68, preferably'four in number, are applied between the outer lip of each fold 41 and the outer surface of the section 25'upon which that fold is formed. p

By the novel operations above described, a stovepipe casing may be'formed with an in-l lll' cil

of the slots ner lining ofsuch hard steel that'it is not practicable to punch it for rivets, or to coi'- rugate it for theV purpose of uniting adjacent sections of the outer lamination. This advantage is achieved yby the forming of adjacent ends of the outer section so that they may interlock to forina Substantially continuous tubular member and which, while it grips and therefore adequately supports the inner lamination, depends for linear tensile strength upon the interlocking of the adjacent ends of the outer sections rather than upon the connection of the adjacent sections of the outerlamination by overlapping sections of the inner lamination. In order to accomplish this structure, the operations above set forth had to be evolved by which each outer lamination section 'enters into an exceedingly tight gripping relation with two adjacent inner sections and in an entirely separate gripping and interlocking relation with an adjacent outer section.

By virt-ue of the combined utility of the above operations it is possible to form a stovepipe casing of sheet metal which has exceedingly high internal wear-resisting qualities and which will not separate even upon the highly improbable event that the inner wear-resisting lamination should actually wear in two. While the stovepipe casing de` 'scribed herein is being fairly extensively used, there has been no instance where the inner lamination has been worn in two.

As a safeguard against the dropping of sections of the innerlainin ation into the well, due totheir being worn by contact with. the drilling tools, a series of slots 70 are provided in spiral relation in tliebody of each Aof the outer sections so as'to permit' spot welding through the slots which will connect each of the inner lamination sections 22 to each of the outer sections 25 by which it is gripped. It is to be understood, however, that the spot welding through tlieslots 70 is notan essential part of the process oi' invention and while it is valuable for the above noted purpose, it does not'add substantiallyV to the linear tensile strength of the casing. At present ten 70 are formed in each of the outer sections 25.

*The diameters in which the casing 17 is made at presentvary between l2 and 24.`

In making casing within these limits, the inner tubularl lamination sections 22 are preferably formed of six gauge sheet high carbon steel wall. The outer lamination sections 25 are preferably formed of eight gauge ductile stamping steel. IVhen the ,A outer laminationsecti ons are formed of eight gauge metal, or heavier, the vstrength of the joints between adjacent outer sections has been proved in actual test to exceed the strength of the body of one of these sections intermediate its ends. In a testing machine a tensile force of two hundred thousand pounds was imposed upon a length of the casing 17 and the casing parted between the joints, the latter being undistorted by this enormous force.

In addition to the stovepipe casing of our invention having a greater linear tensile strength than that of any casing previously made, it is provided with annularreinforcement at frequent intervals without sacrificing the smooth inner surface of the casing. This annular reinforcement prevents collapsing of the casing though it may be subjected to excessive strains as by a shifting of one of the strata 16 through which the well l5 extends. Such a shifting frequency occurs when subterranean pressure has been relieved by a discharge of gas or oil through the well and therefore the reinforcing feature of our stovepipe casing adds greatly to its value. No other stovepipe casing previously made has a structure which provides both a smooth inner surface and annular reinforcing ribs formed integral with the Wall of the casing. v

In all other forms of casing th-e smooth and truly cylindrical inner surface of our casing is lacking either because of the presence of rivets, corrugations, screw couplings orrother features essential to the structure of the casing. In our casing all of these features are eliminated and at the same time a casing is produced which is water-tight and which iS stronger, cheaper, and longer lived than any casing previously known. n

We claim as our invention:

l. In a sheet metal stovepipe well casing, the combination of: a tubular lining formed of a plurality of sections placed end to end; a tubular shell formed of a plurality of sections placed end to end and sheathing and tightly gripping said lining, the shell sections being disposed in break-joint relation with the lining sections; means formed integral with the adjacent ends of said shell sections adapted to interlock when in contacting relation to connect the shell sections whereby said shell constitutes a continuous sheet metal tube; and an annular, thickened, reinforcing bead formed integral with and about each shell section intermediate the ends thereof.

2. In a sheet metal stovepipe well casing, the combination of: a tubular lining formed of a plurality of sections placed endto end; a tubular shell formed of a plurality of sections placed end to end and sheathing and tightly gripping said lining, the shell sections being' disposed in break-joint relation with the lining sections; means formed upon adjacent ends of said shell sections adapted to interlock when brought into contacting relation to connect the shell sections whereloy'saidk shell constitutes a continuous sheet metal tube; and an annular reinforcing fold formed in the metal of each shell section intermediateV the ends thereof.

In testimony whereof, the said MARION R. SHIRLEY has hereunto set his hand at Los Angeles, California, the 24th day of February, 1928, and the said WILLIAM A TROUT and OIIVER C. TROUT have hereunto set their hands at Los Angeles, California, the 13th day of February, 1928. L

MARION R. SIIIPLEY. WILLIAM A. TROUT. OLIVER C. TROUT. 

